Hi Nannyslayer,
Stb Transducer is a 265LH on the TZT3 with a 50/200 600 watt beside it . Also there is a SS175M through the hull in front of it.
Part of the old Lowrance setup. Truth fully I've found it to a fair bit of a learning curve. The 265LH and the 50/200 talk to each other and get a fair bit of interference on High Chirp. Not so bad if I run it Auto cruising at speed. I Really like the Accu fish side of TZT3 with this transducer.
I use more manual settings now but I'm still learning.
Any way getting back to your transducer . For what it's worth I would try to run it deeper in the water. If you are worried about the trim tab effect, just place some washers between the trimtab plate and the ram on the port side ( It Won't need Many). (See the Photos I have already up loaded.)
You might not need as much angle down at the back. I did it because at slow speed sounding around and 4 people up the front my boat has a bow down attitude.
It looks like you have a duck board above the transducer so you might not need a spray plate. If you haven't got a Chirp Transducer try and get one. Hope this helps
Cheers